[github-207] add SLF4JLogger

git-svn-id: https://svn.apache.org/repos/asf/poi/trunk@1884568 13f79535-47bb-0310-9956-ffa450edef68

1 files changed, 157 insertions, 0 deletions

diff --git a/src/java/org/apache/poi/util/SLF4JLogger.java b/src/java/org/apache/poi/util/SLF4JLogger.java
new file mode 100644
index 0000000000..236fc2cee6
--- /dev/null
+++ b/src/java/org/apache/poi/util/SLF4JLogger.java
@@ -0,0 +1,157 @@
+/* ====================================================================
+   Licensed to the Apache Software Foundation (ASF) under one or more
+   contributor license agreements.  See the NOTICE file distributed with
+   this work for additional information regarding copyright ownership.
+   The ASF licenses this file to You under the Apache License, Version 2.0
+   (the "License"); you may not use this file except in compliance with
+   the License.  You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+==================================================================== */
+package org.apache.poi.util;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+/**
+ * An implementation of the {@link POILogger} using the
+ * SLF4J framework. Which itself can be configured to
+ * send log to various different log frameworks and even allows to create
+ * a small wrapper for custom log frameworks.
+ */
+public class SLF4JLogger implements POILogger
+{
+    private Logger log;
+
+    @Override
+    public void initialize(final String cat) {
+        this.log = LoggerFactory.getLogger(cat);
+    }
+
+    /**
+     * Log a message
+     *
+     * @param level One of DEBUG, INFO, WARN, ERROR, FATAL
+     * @param obj1 The object to log.
+     */
+    @Override
+    public void _log(final int level, final Object obj1) {
+        switch (level) {
+            case FATAL:
+            case ERROR:
+                if (log.isErrorEnabled()) {
+                    log.error(obj1.toString());
+                }
+                break;
+            case WARN:
+                if (log.isWarnEnabled()) {
+                    log.warn(obj1.toString());
+                }
+                break;
+            case INFO:
+                if (log.isInfoEnabled()) {
+                    log.info(obj1.toString());
+                }
+                break;
+            case DEBUG:
+                if (log.isDebugEnabled()) {
+                    log.debug(obj1.toString());
+                }
+                break;
+            default:
+                if (log.isTraceEnabled()) {
+                    log.trace(obj1.toString());
+                }
+                break;
+        }
+    }
+
+    /**
+     * Log a message
+     *
+     * @param level One of DEBUG, INFO, WARN, ERROR, FATAL
+     * @param obj1 The object to log.  This is converted to a string.
+     * @param exception An exception to be logged
+     */
+    @Override
+    public void _log(final int level, final Object obj1, final Throwable exception) {
+        switch (level) {
+            case FATAL:
+            case ERROR:
+                if (log.isErrorEnabled()) {
+                    if (obj1 != null) {
+                        log.error(obj1.toString(), exception);
+                    } else {
+                        log.error(exception.toString(), exception);
+                    }
+                }
+                break;
+            case WARN:
+                if (log.isWarnEnabled()) {
+                    if (obj1 != null) {
+                        log.warn(obj1.toString(), exception);
+                    } else {
+                        log.warn(exception.toString(), exception);
+                    }
+                }
+                break;
+            case INFO:
+                if (log.isInfoEnabled()) {
+                    if (obj1 != null) {
+                        log.info(obj1.toString(), exception);
+                    } else {
+                        log.info(exception.toString(), exception);
+                    }
+                }
+                break;
+            case DEBUG:
+                if (log.isDebugEnabled()) {
+                    if (obj1 != null) {
+                        log.debug(obj1.toString(), exception);
+                    } else {
+                        log.debug(exception.toString(), exception);
+                    }
+                }
+                break;
+            default:
+                if (log.isTraceEnabled()) {
+                    if (obj1 != null) {
+                        log.trace(obj1.toString(), exception);
+                    } else {
+                        log.trace(exception.toString(), exception);
+                    }
+                }
+                break;
+        }
+    }
+
+    /**
+     * Check if a logger is enabled to log at the specified level
+     *
+     * @param level One of DEBUG, INFO, WARN, ERROR, FATAL
+     */
+    @Override
+    public boolean check(final int level)
+    {
+        switch (level) {
+            case FATAL:
+            case ERROR:
+                return log.isErrorEnabled();
+            case WARN:
+                return log.isWarnEnabled();
+            case INFO:
+                return log.isInfoEnabled();
+            case DEBUG:
+                return log.isDebugEnabled();
+            default:
+                return false;
+        }
+    }
+}
+